[Gimp-user] how can i...

[flexible fotography <flexiblefotography gmail com>]

hello again, i have another question with (i hope) an easy answer.
i cannot find a keyboard method for ending a tool application. here is the
detail:

when i use fuzzy select, and then use brightness/contrast tool, when i'm
zoomed in and the image fills the screen, i have to re-select the fuzzy
tool and zoom back out to click on the part of the screen with no image in
order to end the fuzzy tool application. is there a keyboard shortcut to
end a tool application?

thank you GIMPers in advance for helping.
michael-leonard